The present invention relates to a device for use in storing a material, such as a liquid, in a metal barrel of the type having a threaded end opening or "bunghole", particularly standard barrels of the type used in the oil industry.
Liquid waste material of a noxious or contaminant nature, such as waste oil, chemicals, etc., is normally stored in metal barrels or drums, particularly of the standard type used in the oil industry, until it can be disposed of by combustion or otherwise. Barrels used for such purpose are usually wellworn, having more or less severe damage and corrosion attacks that may lead to cracks. Consequently such barrels will tend to leak and cause contamination, particularly during transport, when the barrels are often subject to rough treatment.
An attempt to solve this problem is represented by WO, A, 88/08401, which proposes a device for use in storing a material, such as a liquid, in a metal barrel having a threaded bunghole, comprising an impervious bag of a shape and volume adapted to that of the barrel and having a relatively rigid, cylindrical neck portion adapted to be screwed into the barrel bunghole. The cylindrical neck portion of the bag has external threads mating with corresponding internal threads in the barrel bunghole, and having internal threads mating with corresponding external threads of a plug. A serious drawback of this prior device is the fact that the neck portion of the bag, when installed in a standard barrel, protrudes relatively high above the rim of the drum, thereby preventing stacking of the barrels or barrel pallets on top of each other, which is the usual way of storing industrial barrels of the standard type, as used and reused in millions upon millions of situations throughout the world.
Finnish patent publication No. 55 814 which also relates to a plastic bag serving as a lining in a metal barrel proposes a solution to such high neck problem. According to such patent, after the bag has been inserted in the metal barrel, its flexible mouth portion is secured to the barrel bunghole by clamping it between the latter and a deformable plastic ring that is hammered into the threaded barrel bunghole. Then an internally threaded tubular sleeve is forced into the plastic ring and its opening closed by a plug o the like after the bag has been filled. The filled bag is apt to rupture near its clamped mouth portion and the rather complex, multipart clamping and closing device is cumbersome in use.
Also, from GB patent No. 1 392 603 it is known to furnish an apertured drum with an internal plastic liner having a self-supporting neck passage through the drum aperture. However, such liners are for drums having detachable ends which must be removed before the liner can be inserted into the drum.
No doubt the impractibility of the various known devices as described above is the reason why they have not found any widespread use with barrels of the above standard type, in spite of the obvious demand within the field for a device to solve the above leakage problem.